AT TOKYO'S KABUKI-ZA THEATER SATURDAY AFTERNOON, where Steve Parker's "My Geisha" company was shooting premiere scenes for their film-within-a-film, we had lunch with the ageless and affable actor, Edward G. Robinson.

Back in Robinson's dressing room the popular star removed his tuxedo jacket, settled down in an easy chair and lit up a six-inch cigar.

"All right, Ricketts," he scowled, blowing a stream of smoke in our face. "I'll level with you. You don't think I'm here just to make this picture, do you? Naa. I'm here to organize this town. Whataya want — the south side or the west side?" (We modestly accepted the south side.)

This was the Robinson of old speaking, the man who made Little Caesar a byword where movies about the underworld are concerned. Although Robinson has made more than 80 films during his long career, less than 10 of them were gangster movies.

Yet, he is indelibly etched in the public's mind as the tough-talking, cigar-chewing ganglord who would rather rub out an opponent than listen to a lot of backtalk.

Cross the Big Boy and you were likely to wind up in a cement vest.

"THE PUBLIC DOESN'T REALIZE THAT MOST OF MY films had nothing to do with gangsters;" said Robinson. "I did 40 plays on Broadway before I went to Hollywood. Most of them were 'successful failures.' Then I played a gangster in a play called 'The Racket' ... and wound up in Hollywood.

"It took me more than 20 years to work up enough courage to return to Broadway. I kept putting it off ... and the longer I put it off the more difficult it became. Twenty years is a long time, and I was afraid I might fail."

But fail he didn't. Robinson finally moved East for a triumphant, three-year run in "Middle of the Night," the critically and financially successful story of an aging businessman who falls in love with a pretty secretary 30 years his junior.

Pausing to relight his diminishing stogie, Robinson, one of the most imitated actors in show business (every two-bit comic in the U.S. delights in doing his Little Caesar bit), voiced his opinion on the subject.

"I DON'T MIND BEING IMITATED," HE SHRUGGED. "People come up to me on the street and do it. But one never really knows what one really looks or sounds like. I don't think I've ever seen an imitation of myself that I thought was accurate."

Asked about that "G" in the middle of his name Robinson smiled and explained: "It stands for 'God-knows-what,' or 'gangster' ... take your pick. Back when I first became an actor it was popular to have a middle initial.

"But pass this advice along to aspiring young actors: pick a short name. It makes autograph signing much simpler and it's easy to fit on a marquee. At the time I chose my name, I didn't think I would be signing many autographs."

With the lunch hour over and shooting about ready to resume, we got up to leave. But Robinson gripped our right arm. "You know what, Ricketts?" he snarled. "I've changed my mind. This town ain't big enough for both of us. One of us has to go — and it ain't gonna be me!"

So keep the south side, tough guy. Who needs it?